The invention provides a metering box with a protection function. The metering box is used for facilitating the installation of electrical components in a multifunctional metering box. A locking mechanism is arranged between a box door and a box body. The left and right inner walls of the box body are provided with slide rails whose acting surfaces are provided with slide grooves. A plurality of vertically arranged cross beams are arranged between the two slide rails. The cross arms are provided with long holes. Two ends of the cross beams are provided with slide blocks which are slidingly connected to the slide grooves. The slide blocks are provided with locking holes. The slide rails are provided with two columns of adjusting holes which are corresponding to the slide blocks. Bolts are arranged between the adjusting holes and the locking holes. The left side wall of the box body is provided with a heater. The right side wall of the box body is provided with a humidity sensor. The bottom of the box body is provided with a fan. The heater, the fan and the humidity sensor are in a signal connection with a controller. According to the metering box, the installation of electrical components in the metering box can be facilitated, and the electrical components can be protected.